Expansive Clay Soils

What is Expansive Soil?

Expansive clay soils, also known as fat or heavy clay soils, are capable of absorbing water. Because of this property, they can swell up to 10 percent when wet and shrink back down to a smaller volume when dry. These seasonal changes in volume result in shear stresses and lateral and vertical pressures. This causes expansive clay to crack or detach from structures built on top of it. Expansive clays cause billions of dollars worth of damage and repairs each year.

These expansive soils are found across several countries and six continents. They are most common in North and South America, Africa, and Asia. However, they are also found in Europe, including the United Kingdom. This makes them extremely sensitive to environmental factors. Because of their sensitivity to these factors, practitioners need to understand how to predict the volume change behavior of expansive soils. Here are some of the more common examples of expansive soils.

Expansive clay soil is often found in the deserts of Arizona and similar arid regions of the western United States. It is found in riverbeds, valleys, and near the ocean. Native Americans built houses on expansive clay soil because they avoided the problems associated with foundation heave on a sandy foundation. This type of soil is particularly vulnerable to extreme weather conditions. Therefore, it is important to properly plan the foundation of the building and consider all its potential pitfalls.

Stabilizing expansive clay soils involves modifying the composition and structure of the soil through physical and chemical processes. This process will enhance the durability of the soil and reduce the likelihood of collapse. Expansive clay soils are often unstable, so stabilization is necessary to prevent building collapse. In addition, it will reduce the amount of heave in the foundation. In Arizona, large-scale farming operations and city-owned farms use these techniques to enhance the durability of their foundations.

It is important to inspect a house for extensive soil issues before buying it. During the inspection, look for cracks in the walls, misaligned doors and windows, and floor heaving. Knowing what to look for can help you avoid costly repairs in the future. You may need to hire a professional to do this for you. Soil testing is a valuable investment in your home, so don’t be afraid to hire an independent specialist.

A good foundation design involves analyzing the pile behavior. It is based on the mechanical behavior of saturated soil and effective stress in the surrounding unsaturated soil. Expansive clay soils are also characterized by their in situ matric suction, which directly affects the behavior of the pile foundation. Changes in matric suction affect the pile’s load transfer mechanism. The changes in matric suction can affect the load transfer mechanism, causing variations in the soil-pile interface strength properties.

When the soil is too expansive, it can damage the foundation. To avoid these problems, ensure proper grading and drainage away from the foundation. Otherwise, water can enter the concrete and crack the home’s foundation. When expansive clay soils compromise a foundation, the water inside the foundation may eventually be absorbed by the house. The only way to avoid these problems is to avoid construction near the expansive clay soil.